In this study, the investigators will evaluate the efficacy and safety of atorvastatin in SCD patients. At the completion of this trial, the investigators will have an improved understanding of the contribution of endothelial dysfunction to the pathophysiology of albuminuria in SCD. If the data support the hypothesis that atorvastatin is safe and effective in this population, the investigators plan on carrying out adequately powered studies to more definitively evaluate its safety and efficacy in the treatment and/or prevention of albuminuria in SCD.